I'm looking for a decent electret element like the Panasonic WM-61B, to use in a speaker measuring microphone (only requirement: flat frequency response). The only problem is, I can't find any source besides Digikey, and purchasing a single piece would be cost prohibitive. If anyone has an extra one of these on hand and could mail it to me, I would be really grateful. I'll pay a reasonable amount, like $5. Please reply here or send me an e-mail if you could help. Thanks very much.